The analytic properties of the eikonal and U -matrix unitarization schemes are examined. It is shown that the basic properties of these schemes are identical. Both can fill the full circle of unitarity, and both can lead to standard and non-standard asymptotic relations for σel/σtot. The relation between the phases of the unitarised amplitudes in each scheme is examined, and it is shown that de...

We show on gauge invariance grounds that the fine threshold phenomenon is discovered in the radiative decays φ → γa 0 → γπ 0 η and φ → γf 0 → γπ 0 π 0. This enables to conclude that production of the lightest scalar mesons a 0 (980) and f 0 (980) in these decays is caused by the four-quark transitions, resulting in strong restrictions on the large N C expansions of the decay amplitudes. The ana...

It is usually used a complicated combinatorics to prove the Bogoli-ubov — Parasiuk theorem. In the present paper we give a proof of the Bogoliubov — Parasiuk theorem which use a simple combinatorics. To give this proof we interpret Feynman amplitudes as distributions on the space of α-parameters. We will use this technique in the next paper to give a proof that the divergences in nonequilibrium...

We present an alternative approach for calculating helicity amplitudes for processes involving both massless and massive fermions. With this method one can easily obtain covariant expressions for the helicity amplitudes. The final expressions involve only four vector products and are independent of the basis for gamma matrices or specific form of the spinors. We use the method to obtain the hel...

We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines...

Direct channel or absorption effects are first considered for r exchange reactions, and in particular for TNpN. The discussion is then restricted to nondiffractive pseudoscalar-meson baryon scattering reactions, where only two helicity amplitudes define the scattering process. The 6 GeV/c Q amplitude analyses are reviewed; energy dependences of various features of the data are then studied to o...

To understand the short versus long-distance final-state interactions, we have performed a detailed amplitude analysis for the two-body decay J/ψ → 10. The current data favor a large relative phase nearly 90 between the three-gluon and the one-photon decay amplitudes. The source of the phase is apparently the long-distance final-state interaction. Nothing anomalous is found in the magnitudes of...

Games can offer an entertaining alternative to repetitive tasks. In this paper, we propose the use of tangible interactive games for the repetitive training of upper limbs in the therapy of children with Cerebral Palsy (CP). We obtained promising results. The total of four created games succeeded in triggering all the to-be-trained movements properly and in a motivating and entertaining way. A ...

The aim of this study was to determine the most suitable shaking frequency and amplitude for shake harvesting Esfahan's edible fig (Ficus carica cv. Sabz). A hand held limb shaker with adjustable shaking frequency and amplitude was used for this study. A 3x3 factorial experiment with three levels of oscillating frequency (10, 12 and 14 Hz) and three levels of shaking amplitude (20, 32.5 and 45 ...

We present several applications of quantum amplitude amplification to finding claws and collisions in ordered or unordered functions. Our algorithms generalize those of Brassard, Høyer, and Tapp, and imply an O(N3=4 logN) quantum upper bound for the element distinctness problem in the comparison complexity model. This contrasts with (N logN) classical complexity. We also prove a lower bound of ...